Fatty acids and soaps have a long history tracing into antiquity. The art was highly advanced at the turn of the last century (See, for example, “Modern Soaps, Candles and Glycerin”, L. L. Lamborn, Van Nostrand, N.Y., 1906). Weighty tomes such as “Industrial Oil and Fat Products”, A. E. Bailey, Interscience, New York, 1951 and “Fatty Acids”, Ed. Klare S. Markley, Parts 1-5, Interscience, N.Y., 1960-1968 provide a systematic entry-point to the art. “Fatty Acids”, Ed. E. H. Pryde, American Oil Chemists' Society, 1979, discusses fatty acids including some mention of branched types. Structures, separations and synthesis of fatty acids, including some branched examples, are laid out by F. D. Gunstone in “An Introduction to the Chemistry and Biochemistry of Fatty Acids and their Glycerides”, Chapman and Hall, London, 1958. Substantial contributions to methods of synthesis of branched fatty acids were made by James Cason; see, for example, J. Amer. Chem. Soc., Vol. 66, (1944), p.46. Certain branched mixed fatty acids with high levels of impurities were known in wartime Germany, and have several disadvantages. See Bailey cited supra at pages 504-506.
Fatty acids, including branched types, can be isolated from naturally occurring materials such as vegetable, animal, fish, bird or insect oils or bacteria and can be isolated from human skin lipids. Likewise they can be made from petrochemical starting-materials.
Naturally occurring complex mixtures of esters which in principle can be hydrolyzed to fatty acid mixtures for example include those disclosed by Juarez et al, Archives of Biochemistry and Biophysics, Vol. 293, pp. 331-341 (1992); by Nicolaides et al in Biomedical Mass Spectrometry, Vol. 4., pp. 337-47 (1977); and by Ratnayake et al in Lipids, Vol. 24, pp 630-637 (1989). See also Nicolaides et al., Lipids, Vol. 6., pp. 901-905 (1971). Though such disclosures typically identify numerous monomethyl or polymethyl branched fatty acid derivatives as being present in natural systems, useful amounts of individual compounds are typically not secured.
Fatty acids and their derivatives, including certain branched types, have an enormous utility to man and have been used in applications ranging from laundry cleaning agents to anticonvulsive drugs, dermal lotions and cosmetics. See, for example, commonly assigned WO 94/12608 published Jun. 9, 1994. Such derivatives can have limitations, for example off-odors; further, it has not always been recognized which structures (e.g., primary or secondary carboxyl) are of greatest utility. Some branched fatty acids, more particularly, have been shown to have unusual properties, such as low melting points relative to equal carbon number linear analogs. In view of the age and extent of the art, improvements are becoming more difficult to achieve and what at first may appear to be small advances may carry great weight.
Commercially described branched fatty acids of varying availability include a few from Exxon, Shell, Henkel, Sasol and others; see the technical publications of these suppliers. Many of such materials contain quaternary carbon atoms. Perhaps the most common branched fatty acid type useful as a surfactant but too costly and limited in availability for high-volume applications and moreover, lacking in formulation flexibility, is isostearic acid; there are also some short-chain types, for example 2-ethylhexanoic acid, but these are relatively unuseful as surface-active agents. In short, there is a severe limitation in flexibility to the formulator when this handful of currently commercial types of branched fatty acid or mixture is relied on.
There is therefore an ongoing need for improvement in the field of branched fatty acid compositions. Accordingly, it is an object herein to provide such improvements, particularly novel fatty acids, soaps and derivatives, especially those capable of improving one or more of the following technological systems: surfactants and surfactant systems; cosurfactants; builders; antifoams; emollients and skin feel agents; particularly important is to accomplish improvements useful for the formulator of consumer products such as personal care products and laundry and cleaning products.